Quasar variation - no time-dilation found by Mike Hawkins

The observed frequency spectrum of quasar luminosity variation should be
good probe for time dilation. If quasar redshift is caused by Doppler,
then high redshift quasars should show slower variations in luminosity
due to time-dilation caused by their rapid movement away from us. A
paper on this topic was written in 2001 by Mike Hawkins of Edinburgh
University. I find it very impressive. It is cited by Jerry Jenkins
paper "Supernovae Light Curves: An Argument for a New Distance Modulus"
http://arxiv.org/abs/astro-ph/0404207.

Time Dilation and Quasar Variability
M.R.S. Hawkins http://www.roe.ac.uk/roe/staff/
http://arxiv.org/abs/astro-ph/0105073
http://adsabs.harvard.edu/cgi-bin/np...pJ...553L..97H

The timescale of quasar variability is widely expected to show
the effects of time dilation. In this paper we analyse the Fourier
power spectra of a large sample of quasar light curves to look for
such an effect. We find that the timescale of quasar variation does
not increase with redshift as required by time dilation. Possible
explanations of this result all conflict with widely held consensus
in the scientific community.

Hawkins convincingly shows that the degree of optically observed
luminosity variation - measured at frequencies such one cycle per 10
years to one cycle per fraction of a year - is not correlated with the
quasar's redshift. He also determines the relationship between shorter
wavelengths and faster variation - and shows that this can at best
explain only a fraction of the observed effect. This is based on his
own measurements of two decades or so of photographic plates - he is not
relying on anyone else's observations or interpretations.

He seems unwilling to consider this findings a challenge to the Big Bang
Theory:

Taking the various arguments outlined above at face value, and
accepting the case against microlensing, there does not appear to
be a satisfactory explanation for the absence of a time dilation
effect in quasar power spectra. The arguments resting on an expanding
Universe and cosmological distances for quasars seem beyond challenge.
The argument against microlensing is not so secure.


I see a parallel here with the researchers whose apparently assiduous
research failed to find the expected Transverse Proximity Effect with a
foreground quasar. (See: http://astroneu.com/plasma-redshift-1/#TPE )

I see both the lack of TPE and this work on the lack of quasar
time-dilation as separate, excellent, disproofs of the Big Bang Theory.
But the researchers themselves either fail to consider this or silently
reject it, preferring what to me and to many others seems an impossible
alternative explanation. For the TPE people, it is that quasars turn on
and off, or have very limited lifetimes. For Mike Hawkins, it is that
quasar variations are caused primarily by the gravitational microlensing
effects of many dark matter bodies traversing the line of sight.

I think that these researchers evident consternation at their own
results, combined with what appears to be excellent research and data
reduction, makes these two sets of research all the more convincing as
evidence against the BBT.

Below I chase references and Google links for this paper. I found
nothing of substance beyond the Jerry Jensen citation and what follows:

First, two citations from papers by the same author:

Colour changes in quasar light curves
Hawkins, M. R. S.
MNRAS Vol 344 Issue 2 Page 492 - September 2003
http://arxiv.org/abs/astro-ph/0406161

http://adsabs.harvard.edu/cgi-bin/np...MNRAS.344..492

Naked active galactic nuclei
M.R.S. Hawkins 2004 June 7
http://arxiv.org/abs/astro-ph/0406163

but I don't think these add much to the original paper - they seem to
pursue his microlensing theme.

Here are two papers which seem promising.

Fourier Analysis of Gamma-Ray Burst Light Curves: Searching for a
Direct Signature of Cosmological Time Dilation
Chang, Heon-Young
http://arxiv.org/abs/astro-ph/0106220

http://adsabs.harvard.edu/cgi-bin/np...pJ...557L..85C

Heon-Young Chang has some other papers of potential interest.


Can microlensing explain the long-term optical variability of quasars?
Zackrisson, E.; Bergvall, N.; Marquart, T.; Helbig, P.
http://arxiv.org/abs/astro-ph/0306434
http://www.astro.uu.se/~ez/papers/variability.pdf
http://adsabs.harvard.edu/cgi-bin/np...6A...408...17Z

Although controversial, the scenario of microlensing as the
dominant mechanism for the long-term optical variability of quasars
does provide a natural explanation for both the statistical
symmetry, achromaticity and lack of cosmological time dilation in
quasar light curves.

(They accept Haw kins' research and go fishing for microlensing.)

Here, we investigate to what extent dark matter populations of
compact objects allowed in the currently favored OmegaM=0.3,
OmegaLambda =0.7 cosmology really can explain the quantitative
statistical features of the observed variability. We find that
microlensing reasonably well reproduces the average structure
function of quasars, but fails to explain both the high fraction of
objects with amplitudes higher than 0.35 mag and the mean
amplitudes observed at redshifts below one. Even though
microlensing may still contribute to the long-term optical
variability at some level, another significant mechanism must also
be involved. This severely complicates the task of using
light-curve statistics from quasars which are not multiply imaged
to isolate properties of any cosmologically significant population
of compact objects which may in fact be present.

The problems with microlensing seem to be severe enough to write it off
as the major explanation for Hawkins' observations - but they don't seem
to consider that maybe the Universe is not expanding.

I think Mike Hawkins' paper is important and should be discussed more
widely.

- Robin http://astroneu.com

In article ,
(Robin Whittle) writes:

The observed frequency spectrum of quasar luminosity variation should be
good probe for time dilation. If quasar redshift is caused by Doppler,
then high redshift quasars should show slower variations in luminosity
due to time-dilation caused by their rapid movement away from us. A
paper on this topic was written in 2001 by Mike Hawkins of Edinburgh
University. I find it very impressive. It is cited by Jerry Jenkins
paper "Supernovae Light Curves: An Argument for a New Distance Modulus"
http://arxiv.org/abs/astro-ph/0404207.

Time Dilation and Quasar Variability
M.R.S. Hawkins http://www.roe.ac.uk/roe/staff/
http://arxiv.org/abs/astro-ph/0105073
http://adsabs.harvard.edu/cgi-bin/np...pJ...553L..97H

The timescale of quasar variability is widely expected to show
the effects of time dilation. In this paper we analyse the Fourier
power spectra of a large sample of quasar light curves to look for
such an effect. We find that the timescale of quasar variation does
not increase with redshift as required by time dilation. Possible
explanations of this result all conflict with widely held consensus
in the scientific community.

Hawkins convincingly shows that the degree of optically observed
luminosity variation - measured at frequencies such one cycle per 10
years to one cycle per fraction of a year - is not correlated with the
quasar's redshift. He also determines the relationship between shorter
wavelengths and faster variation - and shows that this can at best
explain only a fraction of the observed effect. This is based on his
own measurements of two decades or so of photographic plates - he is not
relying on anyone else's observations or interpretations.

He seems unwilling to consider this findings a challenge to the Big Bang
Theory:

I won't comment on "the big bang has been disproved" since Occam's razor
STILL favours it. Even if not everything in heaven and earth is
understood, a lot of stuff DOES jibe well with the BBT, and any
alternative theory has to explain that as well---and the burden of proof
is on the person who favours an explanation other than the BBT.

Rather, some comments on an issue about which I have (co)written some
papers:

Here are two papers which seem promising.

Can microlensing explain the long-term optical variability of quasars?
Zackrisson, E.; Bergvall, N.; Marquart, T.; Helbig, P.
http://arxiv.org/abs/astro-ph/0306434
http://www.astro.uu.se/~ez/papers/variability.pdf
http://adsabs.harvard.edu/cgi-bin/np...6A...408...17Z

Although controversial, the scenario of microlensing as the
dominant mechanism for the long-term optical variability of quasars
does provide a natural explanation for both the statistical
symmetry, achromaticity and lack of cosmological time dilation in
quasar light curves.

(They accept Hawkins' research and go fishing for microlensing.)

Not really. Accepting his observations, we were intrigued by his idea
that a large part of QSO variability could be explained by microlensing.
Hawkins suggested this in the early 1990s, and the qualitative arguments
(one of which was suggested by the referee and then confirmed by the
data, so the hypothesis actually made a prediction which was verified)
looked intriguing. In later papers, Hawkins put forward what I would
describe as a "toy" or "cardboard" model, and compared this with his
observations. This was (correctly) criticised in several papers.
However, I think that this criticism was misinterpreted by many as
having ruled out the microlensing idea altogether, whereas in fact it
only ruled out Hawkins's over-simplified model. Our goal was to see if
the observations are compatible with a realistic model of microlensing.

Here, we investigate to what extent dark matter populations of
compact objects allowed in the currently favored OmegaM=0.3,
OmegaLambda =0.7 cosmology really can explain the quantitative
statistical features of the observed variability. We find that
microlensing reasonably well reproduces the average structure
function of quasars, but fails to explain both the high fraction of
objects with amplitudes higher than 0.35 mag and the mean
amplitudes observed at redshifts below one. Even though
microlensing may still contribute to the long-term optical
variability at some level, another significant mechanism must also
be involved. This severely complicates the task of using
light-curve statistics from quasars which are not multiply imaged
to isolate properties of any cosmologically significant population
of compact objects which may in fact be present.

We found that the microlensing idea does not hold up: while it is
compatible with the observations Hawkins originally mentioned
(statistical symmetry, achromaticity as a first approximation, less
variability at low redshift, more variability in blue than red (as a
second approximation)), more involved statistical tests show that NO
plausible microlensing scenario is compatible with the observations.

The problems with microlensing seem to be severe enough to write it off
as the major explanation for Hawkins' observations -

I agree.

but they don't seem
to consider that maybe the Universe is not expanding.

That would be throwing the baby out with the bathwater.

Thanks Phillip for responding and clarifying some things about your paper.

RW The problems with microlensing seem to be severe enough to write it
RW off as the major explanation for Hawkins' observations

PH I agree.

Further objections to microlensing being the sole cause include the time
delays in the longer-wavelength changes compared to shorter-wavelength
changes. Here are two diagrams showing 20 or so years of variation in
optical, IR and microwave wavelengths by 3C 273:

http://astroneu.com/misc-files/3c273...-curves-x5.gif
http://astroneu.com/misc-files/3c273...with-lines.gif

derived from:

30 years of multi-wavelength observations of 3C 273
Türler M., Paltani S., Courvoisier T.J.-L., et al., 1999, A&AS, 134,
89 http://obswww.unige.ch/3c273/

Peaks at various wavelengths tend to be correlated in time, with longer
wavelengths lagging the shorter. I think the 3C 273 curves stand as a
good example of a phenomena which has been well studied, for instance:

Optical and radio variability in blazars
Hufnagel, Beth R.; Bregman, Joel N.
http://adsabs.harvard.edu/cgi-bin/np...pJ...386..473H

I think that most or all of the observed variations are compatible with
current theories of black hole accretion disks, with their emissions
energising and reflecting from material at greater distances. Such
variations seem to be required by any black-hole theory, which seems
unavoidable in explaining many other quasar observations. This seems to
rule out microlensing as the sole cause of the observed variation.

Furthermore, if the Universe really is expanding, then if microlensing
was the cause of the observed variations, we would expect time dilation
in the statistical properties of the microlensing of more distant
objects since some or most of that microlensing would be caused by more
distant objects which would be receding from us at higher velocities.
Put another way, if microlensing is responsible for the variations, and
we see no time correlation between its statistics and the redshift of
the quasar, then, if the distance scales with redshift, we might have to
conclude that the microlensing was always occurring close to Earth,
which seems unacceptable for a number of reasons.

I think we can agree that the observed variations in quasar emissions
are entirely, or very largely, due to processes intrinsic to the quasar.

That being the case, since I can't fault Mike Hawkins' observations or
analysis, I propose that his work stands as good, and so-far
unchallenged, evidence that there is no time dilation between our
observations of quasars in two redshift bins: 0.5 to 1.7 and 1.7 to 3.5.

If one group of quasars were receding, on average, faster from Earth
than the other, then we would observe time dilation by differing energy
in their variability time-scale spectrums, unless that effect was
compensated exactly by an equal and opposite change in the nature of
quasars, in general, over time ("evolution"). Such a compensatory
"evolution" seems extraordinarily unlikely, and is rejected by Mike
Hawkins. So I think these observations constitute good evidence that
low redshift quasars are not receding from us any faster than high
redshift quasars.

Assuming the Cosmological Principle is true, then I believe that these
observations constitute good evidence that the average velocity of both
groups of quasars with respect to Earth is zero - which is a direct
contradiction of the Big Bang Theory.

I won't comment on "the big bang has been disproved" since Occam's
razor STILL favours it. Even if not everything in heaven and earth is
understood, a lot of stuff DOES jibe well with the BBT, and any
alternative theory has to explain that as well . . .

It only takes one really good observation, if we decide it is valid, to
disprove a theory. The fact that a theory gives convincing explanations
- and predictions which were later verified - about a whole bunch of
things is neither here nor there. Likewise, the fact that 99% of
astronomers believe the theory to be valid, or that it is an
"established fact", is not relevant. It is not necessary to replace a
disproven theory with anything at all - it is good scientific progress
to cast off the disproven theory and admit that we don't currently have
a theory which explains as much as we previously thought we had explained.

The Big Bang Theory depends entirely on an interpretation of
observations that extra-galactic (or is it extra-galactic-cluster)
objects are moving away from each other in all directions, though this
is sometimes described as "expansion of space-time" rather than actual
movement. In either case, for the BBT to be regarded as valid, this
observed expansion of the positions of galaxies and quasars etc. must
withstand all observational challenges.


and the burden of proof is on the person who favours an explanation
other than the BBT.

I think that is what Mike Hawkin's research provides - a robust
challenge to this theory of explosive expansion.

While the BBT has built a vast array of theoretical constructs on the
basis of this theory of expansion, as far as I know, there are only two
reasons to believe in this expansion exists (not counting potential GRB
light curve time-dilation, which I haven't studied closely).

The first is the general correlation with redshift and apparent-distance
- coupled with the failure so far to show in the laboratory any
mechanism other than Doppler and gravitational redshift which could
explain it. This should be regarded as a tentative finding, at best.
CREIL and two Plasma Redshift theories attempt to provide a non-Doppler
explanation for this redshift - see other threads on sci.astro.research
and my site for references. (Put another way, the BBT is based on the
notion that "photons" always traverse gas and plasma for billions of
years without depositing any energy at all in this medium. A tired light
explanation of "70 km per second per megaparsect" redshift only needs to
account for about 1 part in 13 billion energy loss per year of travel in
the IGM.)

The second is the interpretation of supernovae light-curves - which is
conventionally thought to show direct evidence of time-dilation of
distant supernovae - an effect which most people agree could only result
from the supernovae moving away from us (or appearing to as a result of
the "expansion of space-time") at fractional relativistic speeds.
However this has come under challenge recently, by:

Supernovae Light Curves: An Argument for a New Distance Modulus
http://arxiv.org/abs/astro-ph/0404207 Jerry Jensen 2004-04-06

I think the evidence for Big Bang style expansion is extraordinarily
thin - it seems that the supernova time dilation interpretations rest
primarily with a small number of observations and one or more papers
published around 1996. Jerry Jensen challenges these supernovae
interpretations on several fronts, including that the more distant SNe
are not actually type 1a, and that some corrections applied to the data
early in the processing chain are invalid, because these corrections
assumed the existence of time dilation. The supernovae work relies on
some very challenging "correction" procedures, based on assumptions
about the statistical nature of type 1a SNe which are now being
challenged by Jerry Jenson and other more mainstream researchers he cites.

I think that Mike Hawkins' work depends on a much larger, more
statistically robust, set of observations, and involves a far simpler
set of "corrections", with few, if any, questionable assumptions about
the nature of the distant objects or the mechanisms responsible for the
variation we observe.

I think the onus is on BBT supporters to establish one or more of the
following, or to agree that Mike Hawkins' observations constitute a
robust challenge to the Theory.

1 - Show that the observations are biased in some way which counteracts
the time dilation predicted by the BBT. For instance by showing
systematic errors in the selection process or data reduction - or by
conducting, or analysing, entirely independent observations which
provide evidence about the time dilation of distant quasars.

2 - Show that the "no time-dilation" interpretation of the observations
is incorrect.

3 - Propose that quasars on average have changed their nature over time
so their spectrum of variation frequencies, after time-dilation,
leads to little or no observable change, as apparently found by Mike
Hawkins. This could take the form of a theoretical argument and/or
observations which support this view, including if no theoretical
mechanism is proposed for it.

It doesn't matter whether we have observations or theory to show how the
redshift occurs without the BBT's explosive expansion - all that is
needed for scientific progress to occur is to successfully challenge
these observations and their interpretations, or to recognise that they
stand as a robust challenge to the BBT.

- Robin http://astroneu.com

[[Mod. note -- I apologise for the long delay in posting this article.
The author originally antispam-mangled his domain, and the news server
from which I now post doesn't accept such articles. Since I haven't
been able to contact the author, I've decided not to delay the article
any longer, so I've edited the antispam-mangling to mangle the username
instead. Alas, this means that spam will now get to the author's local
machine. -- jt]]

In article ,
(Robin Whittle) writes:

Furthermore, if the Universe really is expanding, then if microlensing
was the cause of the observed variations, we would expect time dilation
in the statistical properties of the microlensing of more distant
objects since some or most of that microlensing would be caused by more
distant objects which would be receding from us at higher velocities.
Put another way, if microlensing is responsible for the variations, and
we see no time correlation between its statistics and the redshift of
the quasar, then, if the distance scales with redshift, we might have to
conclude that the microlensing was always occurring close to Earth,
which seems unacceptable for a number of reasons.

One has to be careful here. The optical depth for lensing tends to peak
around a redshift of 1, with just a weak dependence on the source
redshift (and on the cosmological model). Also, what about the
velocity: a combination of the velocities of source, lenses and
observer. Depending on how the lenses interact with other matter, their
velocity might increase or decrease with redshift.

That being the case, since I can't fault Mike Hawkins' observations or
analysis, I propose that his work stands as good, and so-far
unchallenged, evidence that there is no time dilation between our
observations of quasars in two redshift bins: 0.5 to 1.7 and 1.7 to 3.5.

True, but if these observations are deemed to be important, then they
should be confirmed by a completely independent observational programme.

It only takes one really good observation, if we decide it is valid, to
disprove a theory.

Right. But, as Sagan said, extraordinary claims require extraordinary
evidence. Such a result would at the very least have to be confirmed by
completely independent observations.

The fact that a theory gives convincing explanations
- and predictions which were later verified - about a whole bunch of
things is neither here nor there.

It's actually quite important. Suppose one finds one observation which
contradicts a given theory. If one can be sure that all observations
are correct, then as you say this disproves the theory. In practice,
however, systematic errors play a role---by definition, an unknown role.
One has to way the probability of this observation being wrong against
the "logical economy" of the theory. An alternative theory which
accomodates this one special observation must also accomodate all the
OTHER observations the first theory did---without resorting to ad-hoc
mechanisms.

Likewise, the fact that 99% of
astronomers believe the theory to be valid, or that it is an
"established fact", is not relevant. It is not necessary to replace a
disproven theory with anything at all - it is good scientific progress
to cast off the disproven theory and admit that we don't currently have
a theory which explains as much as we previously thought we had explained.

Again: in an ideal world, yes; in practice, one has to consider the fact
that that observation might be wrong. Early microscopists reported
observations of homunculi in sperm, and moral theologians of the time
took this as supporting their view that masturbation is murder. But
that observation was wrong (and more than one microscopist saw the
homunculi.)

I think that Mike Hawkins' work depends on a much larger, more
statistically robust, set of observations, and involves a far simpler
set of "corrections", with few, if any, questionable assumptions about
the nature of the distant objects or the mechanisms responsible for the
variation we observe.

Even if his observations are better, one has to keep in mind that a)
there are two quite independent supernova groups and b) the current
wisdom is that we know less about QSOs than supernovae, so the
interpretation is more difficult.

[[Mod. note -- I apologise for the long delay in posting this article.
The author originally antispam-mangled his domain, and the news server
from which I now post doesn't accept such articles. Since I haven't
been able to contact the author, I've decided not to delay the article
any longer, so I've edited the antispam-mangling to mangle the username
instead. Alas, this means that spam will now get to the author's local
machine. -- jt]]

In article ,
(Robin Whittle) writes:

Furthermore, if the Universe really is expanding, then if microlensing
was the cause of the observed variations, we would expect time dilation
in the statistical properties of the microlensing of more distant
objects since some or most of that microlensing would be caused by more
distant objects which would be receding from us at higher velocities.
Put another way, if microlensing is responsible for the variations, and
we see no time correlation between its statistics and the redshift of
the quasar, then, if the distance scales with redshift, we might have to
conclude that the microlensing was always occurring close to Earth,
which seems unacceptable for a number of reasons.

One has to be careful here. The optical depth for lensing tends to peak
around a redshift of 1, with just a weak dependence on the source
redshift (and on the cosmological model). Also, what about the
velocity: a combination of the velocities of source, lenses and
observer. Depending on how the lenses interact with other matter, their
velocity might increase or decrease with redshift.

That being the case, since I can't fault Mike Hawkins' observations or
analysis, I propose that his work stands as good, and so-far
unchallenged, evidence that there is no time dilation between our
observations of quasars in two redshift bins: 0.5 to 1.7 and 1.7 to 3.5.

True, but if these observations are deemed to be important, then they
should be confirmed by a completely independent observational programme.

It only takes one really good observation, if we decide it is valid, to
disprove a theory.

Right. But, as Sagan said, extraordinary claims require extraordinary
evidence. Such a result would at the very least have to be confirmed by
completely independent observations.

The fact that a theory gives convincing explanations
- and predictions which were later verified - about a whole bunch of
things is neither here nor there.

It's actually quite important. Suppose one finds one observation which
contradicts a given theory. If one can be sure that all observations
are correct, then as you say this disproves the theory. In practice,
however, systematic errors play a role---by definition, an unknown role.
One has to way the probability of this observation being wrong against
the "logical economy" of the theory. An alternative theory which
accomodates this one special observation must also accomodate all the
OTHER observations the first theory did---without resorting to ad-hoc
mechanisms.

Likewise, the fact that 99% of
astronomers believe the theory to be valid, or that it is an
"established fact", is not relevant. It is not necessary to replace a
disproven theory with anything at all - it is good scientific progress
to cast off the disproven theory and admit that we don't currently have
a theory which explains as much as we previously thought we had explained.

Again: in an ideal world, yes; in practice, one has to consider the fact
that that observation might be wrong. Early microscopists reported
observations of homunculi in sperm, and moral theologians of the time
took this as supporting their view that masturbation is murder. But
that observation was wrong (and more than one microscopist saw the
homunculi.)

I think that Mike Hawkins' work depends on a much larger, more
statistically robust, set of observations, and involves a far simpler
set of "corrections", with few, if any, questionable assumptions about
the nature of the distant objects or the mechanisms responsible for the
variation we observe.

Even if his observations are better, one has to keep in mind that a)
there are two quite independent supernova groups and b) the current
wisdom is that we know less about QSOs than supernovae, so the
interpretation is more difficult.